Gum disease and Periodontal words | Meaning of dental words New York Periodontist New Jersey | Manhattan, Queens, Nutley, Holmdel, Long Island Abscess: A localized collection of pus in a cavity formed by the disintegration of tissues. Abutment: A tooth or implant used for the support or anchorage of a fixed or removable prosthesis. Acute necrotizing ulcerative gingivitis: Inflammation of the gingiva. Also known as Trench Mouth. Advanced periodontitis: Inflammation of the supporting tissues of the teeth. Alveolar bone: Compact bone that composes the alveolus (tooth socket). Alveolus: The socket in the bone into which a tooth is attached by means of the periodontal ligament. Ankylosis: Solid fixation of a tooth, resulting from fusion of the tooth and alveolar bone. Apicoetomy: 1. The surgical removal of the apex of the tooth root. Most often done in conjunction with root canal therapy. 2. The excision of the apical portion of a tooth root through an opening made in the alveolar cortical bone for removal of a seat of infection.

Apex: The anatomic end of the tooth root. Calculus: A hard deposit attached to the teeth, usually consisting of mineralized bacterial plaque. Candida: Yeast often found in association with oral disease such as ï¿½thrushï¿½. Caverous resorption: Bone loss leaving hollow spaces. Such resorption may appear on radiographs of teeth with vertical root fractures. Cementoenamel, Junction (CEJ): The area at which the enamel and cementum are united at the cervical region of the tooth. Cementum: A mineralized bone-like tissue that covers the tooth root and blends with the periodontal ligament to hold the tooth in place. Chlorhexidine: A biguanide antiseptic agent used to prevent colonization of micro-organisms on the surfaces of skin, mucous membranes, and teeth. Collagen: A main supportive protein of skin, bone and other connective tissues. Crater: A saucer-shaped defect of soft tissue or bone, often seen interdentally. CT graft (connective tissue): Gum tissue grafted to cosmetically correct gum defects. Curettage: Scraping or cleaning of the wall of a cavity or surface by means of instrumentation.

Cusp: A notable pointed or rounded eminence on or near the masticating(chewing) surface of a tooth. Debridement: The removal of inflamed, devitalized, contaminated tissue or foreign material from or adjacent to a lesion. Decalcification: The removal of calcium salts from a bone or tooth. Dehiscence: Drainage site. Dental hygienist: A licensed, professional dental auxiliary who is both an oral health educator and clinician and who uses preventive, educational, and therapeutic methods to control oral disease. Dental plaque: A sticky, colorless film that constantly forms on the teeth. The bacteria in dental plaque is what causes periodontal disease. If plaque is not removed carefully each day by brushing and flossing, it becomes calculus. Dental prophylaxis: Teeth cleaning. Dentin: The chief substance or tissue forming the body of teeth. Dentition: Natural teeth in the dental arch: they may be primary or secondary teeth. Denture: An artificial substitute for missing natural teeth. A complete denture replaces all of the teeth in an arch.

Distal wedge: A periodontal surgical procedure for removal of excessive soft tissue distal to a terminal molar and thus gain access to underlying bone. Edema: An abnormal swelling resulting from an accumulation of watery fluid in a tissue. Edentulous: Without teeth. Enamel: The hard calcified tissue covering the dentin of the crown portion of a tooth. Epithelium: The tissue serving as the lining of the intra-oral surfaces. It extends into the gingival crevice and adheres to the tooth at the base of the cervice. Etiology: The study of the causes of disease which results from an abnormal state producing pathological conditions. Evulsion: The sudden tearing out, or away, of tissue due to a traumatic episode. Excision: A cutting out: removal: the process of amputating or cutting away any portion of the body. Exostosis: A benign bony growth projecting outward from the surface of a bone(tori). Fibroma: A tumor comprised of fibrous connective tissue. Fistula: The drainage tract from an abscess. Flap surgery: The periodontist makes an incision in the gum where periodontal pockets have formed.

He or she reflects the gum flap away, exposing the tooth root and cleans all infection out from the pocket. Bone regeneration procedures such as bone-grafting may be performed at this point. The periodontist then positions the gum to reduce the pocket and promote healing. The incision is sutured closed following the procedure. Frenectomy: The excision of the frenumï¿½the fold of mucous membrane connecting the lip and the alveolar process in the midline of both the maxilla and the mandible. Free gingival gaft: Transplantation of palatal tissue to correct a gum defect. Furca: Furcation. The anatomic area of a multi-rooted tooth where the roots diverge. Gingiva: The gum, tissues which immediately surround the teeth and are contiguous with the periodontal membrane and the mucosal tissue of the mouth. Gingivectomy: The excision of the gum tissue to eliminate periodontal pockets. Gingivitis: The first stage of periodontal disease. The gums usually become red, swollen and bleed easily. This is brought on by the bacteria in dental plaque if not removed on a daily basis.

Grafts: A piece of living tissue placed in contact with injured tissue to repair a defect or supply a deficiency. Granuloma: Proliferation of inflammatory tissue. H Halitosis: A foul or unpleasant breath Hemisection: The surgical separation of a multi-rooted tooth through the furcation area in such a way that a root or roots may be surgically removed along with the associated portion of the crown. The procedure is most frequently performed on lower molars but may be performed on any multirooted tooth. Hyperplasia: The abnormal multiplication or increase in the number of normal cells. Hypoplasia: Defective or incomplete development of normal cells. I Idiopathic: Of unknown causation. Impacted tooth: An unerupted or partially erupted tooth that is positioned against another tooth, bone or soft tissue so that complete eruption is unlikely. Implants: Artificial substitutes for tooth roots. Made from titanium and placed in the jaw, dental implants are either screw, cylinder or blade in form. Prosthetic teeth are attached to the part of the implant that protrudes through the gum. In many ways, dental implants function like natural teeth.

Inflammation: Localized protective response elicited by injury or destruction of tissues, which serves to destroy, dilute, or wall of both in injurious agent and the injured area. Interdental: Situated between the adjacent surfaces of teeth in the same arch. Interproximal: Between adjoining surfaces, such as the proximal surfaces of contiguous teeth. Labial surface: Toward the lip. Lesion: An injury or wound. Leukoplakia: A condition marked by the development on mucosal tissue of white, thickened patches which cannot be rubbed off and which sometimes show a tendency to fissure. It is common in smokers, and the affected tissue sometimes becomes malignant. Lichen planus: An inflammatory mucocutaneous disorder characterized by discrete skin papules with a keratinized covering with a keratinized covering which often appears in the form of adherent scales. These oral lesions are common and sometimes the only manifestation of the disease. Ligament: The connective tissue structure that attaches the roots of the teeth to the bone. Lingual surface: Pertaining to the tongue. Maintenance therapy: An ongoing program designed to prevent periodontal disease from recurring for patients who have undergone periodontal treatment.

Also referred to as supportive periodontal therapy. Malocclusion: Imperfect occlusion of the teeth. Mandible: The lower jaw. Mastication: The process of chewing food in preparation for swallowing and digestion. Maxilla: The upper jaw. Mesial surface: Toward or situated toward the middle, or the center of the dental arch. Mobility of teeth: The degree of looseness of a tooth. Mucogingival: A generic term used to describe the mucogingival junction and its relationships to the attached gingiva, alveolar mucosa, frenula, muscle attachments and the buccal and labial vestibule. Mucosa: The tissue lining the oral cavity. N Necrotizing ulcerative gingivitis: A severe, recurring infection of the gums. This disease can include spontaneous bleeding from the gums, pain, a foul smell and dead or dying gum tissue. Recurrent episodes of the disease can lead to bone loss. Also called trench mouth. Usually associated with poor oral hygiene along with the triad of: 1) smoking, 2) stress and 3) poor nutrition.

Necrosis: Death of tissue, usually as individual cells, groups of cells, or in small localized areas. Occlusal: Pertaining to the contacting surfaces of opposing teeth. Occlusion: Any contact of opposing teeth. Oral hygiene: Removal of bacterial plaque with brushes, dental floss, and other special instruments. The maintenance of oral cleanliness. Oral prophylaxis: The removal of plaque, calculus, and stain from the exposed and unexposed surfaces of the teeth by scaling and polishing as a preventive measure for the control of local irritational factors. Osseointegration: The attachment of the bone to a dental implant. This usually takes three to six months after the implant has been placed in the mouth. Osseous: Pertaining to bone. Osseous surgery: Any surgical procedure that deals with the bony support of the teeth. Osteogenesis: Development of bone: formation of bone. Osteogenic: Any tissue or substance with the potential to induce growth or repair of bone. Osteomyelitis: Inflammation of bone marrow and adjacent bone. Osteoperiosteal: Pertaining to bone and its periostum.

Osteoplasty: Reshaping of the alveolar process to achieve a more physiologic form without removal of alveolar (supporting) bone. Palate: Hard and soft tissues separating the oral and nasal cavities. Papilla: The portion of gingiva occupying the interproximal space between adjacent teeth. Parasthesia: An abnormal sensation, such as burning, prickling, or numbness. It is usually caused by nerve injury and sometimes follows surgical procedures. Pathogen: Any disease-producting micro-organism or material. Periapical: Relating to tissue surrounding the apex of a tooth. Pedicle graft: A graft elevated from a donor site, which remains attached at its base for nourishment and is transferred to an adjacent recipient site. Periodontal: Situated or occurring around a tooth. Periodontal ligament: The tissue that attaches the tooth to the bone. Usually destroyed by advanced cases of periodontal disease, creating increased mobility of the teeth. Periodontal pocket: Toxins in plaque destroy the gum and connective tissues beneath the gum line. The gums pull away from the teeth, forming a pocket (space).

As the disease progresses toward the bone, the pocket fills with plaque and infection. If not treated, the bone and connective tissue surrounding the tooth may become so severely damaged that the tooth will fall out or need to be extracted. Periodontics: That branch of dentistry that deals with the diagnosis and treatment of diseases and conditions of the supporting and surrounding tissues of the teeth or their implanted substitutes. Periodontitis: Inflammation of the supporting tissues of the teeth. Periodontium: The tissues that surround and support the teeth, including the gums, periodontal ligament and bone. Plaque: Any organized mass, consisting mainly of micro-oraganisms, that adheres to the tooth or occupies the gingival crevice. Polyp: A pedunculated tumor arising in a mucous membrane. Posterior: Behind, situated to the back of. Preventive treatment: Those procedures performed at intervals that assist the periodontal patient in maintaining dental health. Probe: A slender instrument with a blunt end suitable for use in exploring a channel, wound or pocket. Prognosis: A prediction as to the progress, course, and outcome of a disease. Prosthesis: The replacement of any part of the human body by an artificial part.

Prosthetics: The art and science of supplying missing parts of the human body. Provisional splint: A device used to provide temporary stabilization of mobile teeth. Pulp: The richly innervated and vascularized connective tissue contained within the pulp chamber and root canal of a tooth. Pulp Cavity: The internal space within a tooth which normally houses the dental pulp. Pulpectomy: The complete removal of the dental pulpï¿½root canal therapy. Purulent: Containing pus. Pus: A liquified product of inflammation consisting of leukocytes, degenerated tissue elements, tissue fluids and micro-organisms. Pyorrhea: Flow of pus from a periodontal lesion. Radicular: Pertaining to the root of a tooth and its adjacent structures. Radiopacity: The lighter hues on a x-ray. Radiolucence: The dark hues on a x-ray. Recall maintenance: An extension of periodontal therapy. The continuing periodic assessment and prophylactic treatment of the mouth. Rapidly progressive periodontitis: A rare form of periodontal disease which affects young adults typically in the early twenties through mid-thirties.

The disease is characterized by severe inflammation of the gums and a quick onset of the disease. May be related to several forms of rare systemic diseases including diabetes mellitus Type 1, Down's syndrome, Papillon-Lefevresyndrome, and AIDS. Recession: Location of the gingival margin apical to the cement to enamel junction. Refractory periodontal disease: A form of recurring periodontal disease resistant to proven treatment methods which may reflect an underlying systemicor immunologic condition. Refractory: Persistent, not readily responding to treatment. Ridge augmentation: A surgical procedure to restore a deformity in the bony ridge. Root: The anatomic part of a tooth normally within the alveolar bone and attached to it by the periodontal ligament. Root amputation: Removal of a root from a tooth. Root scaling and planing: A non-surgical procedure where the periodontist removes plaque and calculus from the periodontal pocket and around the tooth root and smoothes the root surfaces to promote healing. Root planing: A procedure designed to remove cementum or surface dentin that is rough, impregnated with calculus, or contaminated with toxins or microoraganisms.

Root resorption: Loss or blunting of some portion of a root. Saliva: The tasteless, clear fluid secreted by the major and minor salivary glands. Scaling: Instrumentation of the crown and root surfaces of the teeth to remove plaque, calculus and stains. Sextant: One of the six relatively equal sections into which the dental arches can be divided. Soft palate: The posterior, mobile part of the palate. Soft tissue: Any noncalcified tissue. Splint: An appliance or device employed to prevent motion or displacement of loose teeth. Stent: An acrylic appliance used as a positioning guide or support. Subgingival calculus: Calculus that is apical or below the gum line. Sublingual: Area below the tongue. Sulcus: A shallow fissure between the gingiva and the tooth. Supporting structures: Those tissues immediately surrounding a tooth and connected with it. Supraocclusion: Teeth usually out of contact with opposing members which have erupted beyond the occlusal level of adjacent teeth. Over-erupted. T Temporomandibular joint: TMJ-The connecting, sliding hinge mechanism between the lower jan and the base of the skull.

Tomogram: An x-ray of a selected layer of the body. Gives a projection of the cross section of bone determining width. Trauma: An injury or wound. Trench mouth: Inflammation of the gingiva. Tuberosity: A bulbous protuberance or elevation of a bone. Periodontium: gingiva, periodontal ligament, alveolar bone cementum, covering the root of the tooth alveolar bone periodontal ligament Each of these components is distinct in its location, tissue architecture, biochemical and chemical composition. They have their own distinct functions and are capable of adaptation during the life of the structure. 1. Gingiva or the gum Gingiva is a soft tissue that overlays the jaw bone and surrounds the teeth providing a seal around them. Gingival tissue is tightly bound to the underlying bone creating an effective barrier (when healthy) for periodontal insults to deeper tissues. Healthy gingiva is usually coral pink, but may contain melanin pigmentation. Healthy gingiva has a smooth "arcuate" appearance around each tooth, a firm texture that is resistant to movement and no reaction (such as bleeding) to normal disturbance such as brushing or periodontal probing.

healthy gingiva Gum infection, called gingivitis , occurs because of microbes in plaque placed on the tooth, if oral hygiene is poor. Changes in color, particularly increased redness, together with edema or swelling and an increased tendency to bleed (for example during teeth brushing), suggest an inflammation due to the accumulation of bacterial plaque. In a more advanced stage of infection, a gingival retraction may occur; this leaves part of the roots naked. gingivitis caused by the accumulation of bacterial plaque gingival recession Inflammation of the gums is the first stage of the periodontal disease. An early treatment is indicated, before the disease advances to a deeper tissue leading to a poorer prognosis. 2. Cementum Cementum is a specialized calcified substance covering the root of a tooth. It is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament. Cementum is formed continuously throughout life because a new layer of cementum is deposited to keep the attachment intact as the superficial layer of cementum ages. It has a light yellow colour and the highest fluoride content of all mineralized tissues. 3.

Alveolar bone The alveolar bone is the bone of the jaw that contains the tooth sockets (also known as dental alveoli or alveolar process) on bones that hold teeth. The alveolar process contains a region of compact bone (called the lamina dura) which is attached to the cementum of the roots by the periodontal ligaments. Like any other bone in the human body, alveolar bone is modified throughout life ; under the effect of various external factors, it may suffer processes of bone resorption or bone formation. 4. Periodontal ligament The periodontal ligament is a specialized connective tissue that attaches the cementum of a tooth to the alveolar bone. They are a network of elastic fibres that help support the tooth inside the alveolar bone socket. The functions of the periodontal ligaments include attachment of the tooth to the bone, support for the tooth, formation and resorption of bone during tooth movement, sensation, and eruption. When pressure is exerted on a tooth, such as during chewing or biting, the tooth moves slightly in its socket and puts tension on the periodontal ligaments. This is called tooth physiologic mobility.

The periodontium exists for the purpose of supporting teeth during their function ; a constant state of balance always exists between the periodontal structures and the external forces. Most of the times, periodontal diseases are caused by bacteria from the dental plaqueDental plaque is a biofilm, usually a pale yellow, that develops naturally on the teeth formed by colonizing bacteria trying to attach themselves to the tooth's smooth surface. which is adherent to tooth surfaces. In case of bacterial infections, the first barrier is the gum. In the absence of treatment, the infection progresses to the periodontal ligaments and the alveolar bone involving the progressive loss of the alveolar bone around the teeth which can lead to the loosening and subsequent loss of teeth. Periodontics is the dental speciality that relates specifically to the care, maintenance and treatment of the periodontal tissues. Mouth Anatomy - Overview Parts of the Mouth • Basic Human Mouth Anatomy The Human Mouth The human mouth is a complex structure that consists of both hard and soft tissues forming a hollow cavity. The mouth anatomy features several components including the jaws, teeth, gums, tongue, palate, cheeks, lips, which all together contribute in making possible the various functions of the mouth .

The mouth is also referred as oral cavity or buccal cavity. The main parts of Human Mouth Anatomy The mouth provides the opening through which food and air can enter the human body. Its anatomic boundaries are defined by the lips at the front, the cheeks at the sides, the tongue and floor of mouth at the bottom, the palate at the top, and the oropharynx at the back. The different parts of the mouth play an important role in our daily lives. They work together to chew, grind and swallow foods, distinguish tastes, speak, and express our emotions. The main parts of the mouth anatomy include the following: The Lips are the soft parts of tissue that form the anterior boundary of the mouth. They can seal the oral cavity and contribute in several behavioral expressions such as kissing or laughing. The Cheeks form the sidewalls of the mouth. The Teeth are the white colored calcified structures within the lower and upper jaws, which we use for chewing. Periodontium is a group of supporting tissues that surround teeth and keep them in place. The Gingiva (Gums) is the pink soft tissue that surrounds teeth and covers the jaw bone.

The Periodontal Ligament is a layer of connective tissue fibers which hold the tooth anchored inside the alveolar socket of the jaw. Alveolar process is the part of alveolar bone around the tooth sockets where teeth roots are anchored. The Tongue is a muscular organ that helps us taste foods, chew and swallow them. It contains a large number of ‘taste buds’ that can sense the 4 main tastes: sweet, sour, salty, and bitter. Jaws are the two bony structures that form the skeleton of the mouth and carry the 32 human teeth. The upper jaw, called ‘maxilla’, is fixed with the skull and holds the top row of teeth. The lower jaw also known as mandible is the largest, strongest and the only movable bone of the face. Its ability to move almost in all directions is important for our ability to chew properly. Temporomandibular Joint is the joint that connects the lower jaw (mandible) with the skull. The Palate is the roof of the mouth, separating it from the nasal cavity. It is divided into hard and soft palate. The Salivary Glands provide our mouth with saliva.

There are 3 pairs of major salivary glands, and hundreds of smaller ones around the mouth. Saliva is a biological fluid that moistens and protects the mouth, starts break down foods with its enzymes, and facilitates swallowing. The Floor of the Mouth is formed mostly by the tongue and by mucous membranes that extend from the base of the tongue to the gums of the lower jawbone. The Muscles of the mouth help us perform the controlled movements of the various parts of the mouth (jaw, lips, tongue, cheeks) so that we can eat, speak and express ourselves. Periodontal Disease: Engineering the Future of Care See All Continuing Education Practical Oral Care for People With Developmental Disabilities – This booklet presents an overview of physical, mental, and behavioral challenges common in patients with developmental disabilities and offers strategies for providing oral care. Facing the Future: NIDCR Researchers Offer Their Vision for the 21st Century FacingTheFutureRadEditor1 Periodontal Disease: Engineering the Future of Care In the 1950s, soon after NIDCR’s founding, millions of Americans often flipped on their black-and-white tube televisions and watched commercials that warned of a tongue-twisting condition called gingivitis.

As the ads warned, gingivitis was step one on the road to chronic gum, or periodontal, disease and tooth loss. “Most scientists are optimistic that tissue engineering, with its sophisticated mix of biology and chemistry, will be more predictable in the years ahead.” Today, researchers now know that gingivitis does not necessarily lead to advanced periodontal disease. However, a confluence of factors can induce chronic inflammation of the gingiva in some people. These factors include lifestyle choices, such as an addiction to tobacco; diabetes or another underlying health condition that compromises one’s ability to heal; a susceptibility to gingival infections; and an over reactive immune system. If left unchecked, periodontal disease gradually will degrade the four tooth-supporting tissues of the periodontium – gingiva, periodontal ligament, cementum, and bone. As the television ads from the 1950s correctly concluded, advanced periodontal disease will lead to tooth loss. Today, a trip to the periodontist typically entails anti-infective therapy coupled with scaling and planing of the inflamed tissue. Periodontists also have been eager to employ the latest biological discoveries to regenerate damaged gingiva, ligament, and bone.

Although today’s tissue regeneration techniques remain works in progress, research on this front continues to progress nicely. Most scientists are optimistic that tissue engineering, with its sophisticated mix of biology and chemistry, will be more predictable in the years ahead. To present the research themes are two scientists with long and productive track records in this area: Dr. William Giannobile, a researcher at the University of Michigan in Ann Arbor; and Dr. Pamela Robey, an NIDCR scientist in Bethesda, Maryland. William Giannobile University of Michigan Ann Arbor, Michigan You oversee your own laboratory and head a clinical research center at the University of Michigan. You also find the time to see patients in private practice? I’m also a practicing periodontist, and I continue to treat patients in a private practice here in Ann Arbor. So you’ve both seeded and directly benefited from the research? I think so. As a practitioner, I’ve benefited from the advancements in biomaterials research, various bone grafting techniques, guiding tissue membranes that separate the bone from the connective tissues, and anti-infective therapies to arrest or slow the progression of periodontal disease. But there’s still a ways to go? That’s right.

Periodontal treatment today remains fairly unpredictable in terms of getting stable, long-term results. That’s especially true for regenerating the various parts of the periodontium - bone, ligament, cementum, and mucosa. But there have been some nice advancements, and I just mentioned a few of them. I think the combination of research progress and the continued unpredictability of treatment has, to some extent, shifted the periodontist’s role. How so? About 20 years ago, most restorative dentists would contact periodontists with referrals and say, “Do your best. See how many more years you can help this patient eke out of these teeth.” Now, the mindset is much different. Because of the unpredictability of regeneration and the challenge of controlling a chronic immune response, many practitioners don’t want to run the risk of trying to save the teeth. Many advise their patient to have the questionable teeth removed and replaced with dental implants. But as a researcher and periodontist, I continue to support the profession’s founding principles to save teeth whenever possible. For that reason, I see a lot of areas that we need to explore to develop more predictable therapies, especially when regenerating the damaged tissues of the periodontium.

And the biology is there for the taking? I think so. You can see it in the scientific literature each and every month. You also can see it in the ideas that have entered the clinical research pipeline. The four research areas that hold the key to a future of periodontal tissue engineering and regenerative medicine. For example? Growth factors. Platelet derived growth factor and the bone morphogenetic proteins are both now FDA approved and have entered into the clinical arena over the last two years. Although these growth factors have sometimes incorrectly been held up as a panacea for tissue regeneration, they are indeed very important advancements. Keep in mind, though, periodontal disease is an extremely complex condition. Tissue regeneration alone is not the answer. We need to push the anti-infective/host modulation side, too, and ensure that the patient’s immune response doesn’t turn chronic and self-destructive. And that self destruction is of an inherently complex environment? Absolutely. We essentially have a tooth – an avascular mineralized tissue - that protrudes through soft tissue, where it is under constant microbial attack. The tooth is rooted in bone, anchored by ligament, and dependent on supportive tissues in dentin and cementum.

These tissues have specific geographic junctions, abilities to bond, and load-bearing qualities. What’s more, all of this complexity is rolled into a tight biologic space. We often talk about millimeters of eroded bone. Millimeters are very significant in the support of teeth. There’s just nothing like the periodontium in the rest of the body. So how do you make tissue regeneration more predictable? I think interdisciplinary collaborations hold the key. We need scientists with training in infectious disease, biomedical engineering, molecular and cell biology, genetics, and clinical research. What about technology development? Discovery and technology development typically go hand in hand. A good example is the progress in high resolution imaging techniques. They produce images of bone damage that are so accurate, we literally can construct in the laboratory three dimensional scaffolds that fit perfectly into the periodontal pockets and deliver regenerative factors. This hasn’t yet reached the clinic, but it suggests the following scenario. The surgeon images the tooth/bone lesion and says to the patient, “Okay, I can quickly make this scaffold, and it will be loaded with growth factors or stem cells. We’ll just drop it into the defect.” Right now, the surgeons carve out the decalcified bone as best they can.

It’s just not efficient. We talked a moment ago about the biology being there for the taking. If the scaffolds and their growth-promoting cargo now can be more precisely delivered, that raises the issue of timing. You need to drop in the growth factors at the right time and in the right sequence. That’s an important point. Researchers have begun to look at the process in a more systematic way. But defining the biology is even more important from a diagnostic standpoint. Patients respond differently to treatment. Right, it drives periodontists crazy. But it makes perfect sense. Periodontal disease represents a spectrum of disease. Patients are infected with various pathogens, their immune system reacts differently to the infection, and they arrive in the periodontist’s office with various underlying conditions and habits. If informative protein markers could be identified in patients, at the front end of the visit, we could begin to tailor treatment to their specific needs. This broader biology base takes us back to the clinical pipeline that you mentioned a moment ago. With greater diagnostic specificity, periodontal patients no longer would be lumped together in clinical trials. It would be possible to subcategorize them and begin to customize treatment.

That’s why I think we’re going to be looking more at these designer therapies for patients. With different molecular diagnostic approaches, we’ll have certain patients who really respond well to a given treatment; whereas we have others who have always been lumped together into this non-responder group. Why are they considered to be non-responders? That’s where the diagnostic side would really benefit them. These therapies open up the future use of pharmacogenomics, or individualizing treatment to the patient’s specific form of periodontal disease. Pamela Robey National Institutes of Health Bethesda, Maryland You’ve said if five people of different scientific backgrounds were chatting, it’s possible they’d arrive at five different definitions of the term “stem cell.” I know this is an issue that you’ve thought long and hard about. What is a stem cell? I think any definition must be based on a stem cell’s activity in the body, not necessarily its traits in a culture dish. So, starting there, I think everyone would agree on two broad defining features. One, a stem cell must give rise to more mature daughter, or progenitor, cells that can differentiate into cell types that are needed to maintain a tissue structure.

For example, in the hierarchy of bone formation in adults, stromal stem cells reside in the bone marrow. When prompted to repair, they beget not only the osteo-chondro-progenitor daughter cells that form bone or cartilage, depending on the tissue microenvironment. They also beget the stroma that supports blood formation and marrow fat cells. It’s kind of like reading the Old Testament Book of Numbers. The patriarchal stem cell begets sublineages of cells. Right, and this theme is played out throughout the body. We see it in bone and cartilage, and we see it in dentin. What’s the second defining feature? Self renewal. A stem cell must have the ability to produce a new generation of stem cells. So, as they churn out more mature daughter cells, they also must produce daughter cells that remain stem cells. Without self renewal, the stem cells that populate a given tissue would die their natural deaths and take with them the ability to regenerate and maintain a tissue structure. A single bone marrow stromal stem can reform a bone/marrow organ. Why has the definition of stem cell gone off in all directions? It’s the vagaries of cell culture.

Because scientists typically study stem cells in a culture dish, they describe certain characteristics that may or may not relate back to what they do in the body. For example? Well, two things come to mind. A lot of people say that a stem cell is undifferentiated. But that may be a misnomer. It may be that a fully differentiated cell, under the proper conditions, can revert back and become a precursor cell or maybe even a more primitive cell like a stem cell. As long as a cell has an intact nucleus, nothing is really impossible. Secondly, some say a stem cell has the ability to replicate almost endlessly. But that isn’t necessarily the case either. Even the best characterized stem cell - the hematopoietic stem cell - is not immortal. Each hematopoietic stem cell can only repopulate blood cells a certain number of times before it becomes exhausted. How does this “stemness” translate to the periodontium? Let’s start with the periodontal ligament. We know it’s possible to take a periodontal ligament, and treat it with enzymes to release single cells.

Within that mixed population of cells, there are some that have the ability to recreate fibers that look a lot like those in a periodontal ligament. Whether the fibers can function as a periodontal ligament I think is still on the table for discussion. These cells were discovered here at NIDCR about four years ago, and this lead is actively being pursued. It’s also not clear where the cell comes from, and whether it’s truly a stem cell or a useful progenitor cell. I think that is something that we need to take into consideration. What do you mean? Having a stem cell is a wonderful thing. Knowing about it is a wonderful thing. But the slightly more committed progenitors also can do wonderful things. We shouldn’t dismiss them just because they don’t self renew or produce more than one cell type. If they’re useful in a regenerative way, that’s fine. They don’t have to be a stem cell to be useful. What about alveolar bone of the tooth socket? Stem cells that make bone have been under study since the mid 1990s. Obviously, they have great potential in regenerating the periodontium.

If you don’t have bone to anchor the tooth, you have no foundation. But we really need to know how this type of bone is different from the axial and appendicular bone found elsewhere in the body. They have a different embryonic origin, and their properties appear to be slightly different. We don’t know how that is. Nor do we know the impact of these differences. For example, can we take bone marrow from the iliac crest of the pelvis and use it to regenerate craniofacial bone, including alveolar bone? That’s a huge question, and we really don’t know much about it. What about cementum? Well, I just mentioned the periodontal ligament cells. They also make something that appears to be cementum. In addition, a number of years ago, we took shavings of cementum and could get cells to grow out of those shavings in a clonal fashion. When we took the cells, put them in a scaffold, and transplanted them into our animal model, they formed tissue that resembled cementum. The problem is we don’t really know whether cementum is different from bone. We don’t have any cementum specific markers to answer that question.

It may just be that osteogenic cells form a cementum-like structure when they are in close proximity to dentin-forming cells. So, the boundaries between cementum and bone are very subtle. It’s difficult to say that they are truly two distinct entities. Maybe under the right conditions, cells that normally would be osteogenic could be made to be cementogenic. Are you confident that the regeneration of the periodontium will be doable down the road? I am confident. We have cells that we can begin to use to try and create a viable tooth. But there is a major hurdle in trying to construct a root that will provide a solid anchor within the jawbone. And we need to bring a broader array of expertise to the table. We need more people with expertise in bioinformatics, biomaterials, biochemistry, and clinicians to help us design appropriate animal models that mimic a given human disease. There can be a perception that it’s only a tooth. It’s not going to kill you, if you don’t have one. But try to tell that to somebody with a bad tooth ache. Dental problems cut across all aspects of society, and their solutions potentially benefit everyone.

Secondly, the mouth is readily accessible, unlike the body’s internal organs such as the pancreas or liver. The lessons learned in the oral cavity might not be a perfect fit in learning to better treat osteoporosis or kidney cancer, but they will have applicability. FacingTheFutureRightboxRadEditor Periodontal Disease: Engineering the Future of Care Connect: Tooth Anatomy - Tissues of a Tooth Tooth Anatomy - Tissues of a Tooth The Anatomy of a Tooth Although humans have 4 different types of teeth with significant variations in their external morphology, they all share a common internal dental anatomy. All human teeth consist of 3 main layers. The external and hardest of all layers is the enamel, underneath of enamel there is dentin, and at the center of the tooth lies the softer and live part of the tooth, the pulp. A basic knowledge of the internal anatomy of the tooth and its structure is necessary in order to understand the development of several dental conditions, their causes and their treatments. If we take a section of a human tooth we will be able to distinguish 4 different types of tissues, enamel, cementum, dentin, and pulp tissue.

The main characteristics of each part of the tooth structure are described in this article (for more detailed information about each one follow the links to the specific pages). The main parts of tooth anatomy are Enamel , Dentin , Cementum , and Pulp . The Tooth Enamel Enamel is the outermost layer of the tooth structure of the crown, the part of the tooth that is above the gums. Dental enamel is the hardest and most mineralized substance in the human body. It looks like bone but it is much harder, denser, and its composition is 96% inorganic. Dental enamel offers a protective cover to the entire top of the tooth with its thickest point at the cusps of the tooth. It becomes thinner at the edges of the tooth closer to the gum line, up to the cement-enamel junction (CEJ) where it is substituted by the cementum that covers the root. It is slightly translucent, so any change in the color of the underlying dentin, either due to the development of tooth decay, or due to discoloration usually becomes visible through the enamel. Its natural color can vary from grayish white to yellowish. Although dental enamel is the hardest tissue of the human body, it is very vulnerable.

Due to its very dense mineral structure, it is highly susceptible to acidic damage (demineralization), the main cause of tooth decay . Enamel is also very brittle, especially when not supported by sound underlying dentin. The main disadvantage of dental enamel is that it lacks the ability of repairing itself, as bones have. Any structural damage to the tooth enamel is permanent and can’t be repaired naturally by our body. The Cementum Cementum is the outer layer of the tooth structure for the root part of the tooth which lies under the gum line. It is a bonelike material, almost as hard as enamel, but with a less inorganic composition. Cementum is light yellowish in color, slightly lighter than dentin. It is not translucent as the enamel. The main function of cementum is to protect the roots and anchor the teeth in their sockets inside the jaw bone. A network of fibers made of connective tissue (known as periodontal ligament) connects the cementum with the alveolar bone and keep the tooth steady in its socket (for more details see ΄periodontium΄).

It is more susceptible than enamel to tooth decay, especially due to the higher accumulation of bacterial plaque and dental calculus along the gum line, or underneath it (sub-gingival plaque). Unlike enamel, cementum is formed continuously throughout the life of the tooth to compensate for the substance loss due to tooth wear, and to allow for the attachment of new fibers of the periodontal ligament to the surface of the root. The Dentin Dentin is a bone-like material that makes up most of the tooth's structure. It is covered by the enamel in the crown and by the cementum in the root area of the tooth. It engulfs and protects the living part of the tooth, the pulp tissue. Dentin has a light yellow color, which gives the tooth its natural color prevailing through the almost translucent enamel. It consists of 70% inorganic materials, with a spongy, porous structure made of tubules extending from the enamel to the pulp chamber. Nerve endings enter the dentinal tubules and may transmit signals such as pain in response to external stimuli. Dentin is harder than bone but softer than enamel. It becomes very vulnerable to tooth decay if the protective cover of enamel or cementum is lost or weakened.

However, the dentin is a living tissue, so it has the ability for some degree of growth and repair in response to certain physiologic and pathologic conditions. The Dental Pulp The dental pulp is the soft living tissue of the tooth. It can be found in the pulp chamber, a cavity in the center of the crown of each tooth, and inside the root canals which connect the pulp cavity with the opening at the root tip (apex) and through that with the rest of the body. The pulp contains blood vessels, connective tissue, nerves, and other cells including odontoblasts, fibroblasts, macrophages and lymphocytes. The main function of the pulp is providing sensation and nourishment to the tooth, and the formation of dentin and cementum. The pulp tissue responds to irritation either by forming reparative secondary dentin for protection against the source of irritation or by becoming inflamed. The pulp, as the living part of the tooth, has a high risk of infections. If bacteria manage to reach the pulp, e.g. due to tooth decay or through a crack of the tooth, they cause inflammation which is usually very painful due to the high pressure that is developed inside the enclosed space of the pulp chamber.

If the pulp is infected and a dental abscess has developed, a root canal therapy is necessary to prevent further damage. Structure of Teeth » How to look after your teeth » Introduction » Dental Health Foundation Professional Development Structure of Teeth The tooth has two anatomical parts; the crown and the root. The crown is the part of the tooth that is normally visible in the mouth (above the gum line). The shape of the crown determines the function of the tooth. The root of a tooth is the part embedded in the jaw. It anchors the tooth in its bony socket and is normally not visible (below the gum line). The gum line is where the tooth and gums meet. The anatomy of teeth and the mouth structures which surround and support them are described below. Structures of the tooth Enamel The hard outer layer of the crown. Enamel is the hardest substance in the body yet it can decay if teeth are not cared for properly. Dentine Not as hard as enamel, forms the bulk of the tooth and can be sensitive if the protection of the enamel is lost. Pulp Soft tissue containing the blood and nerve supply of the tooth. The pulp extends from the crown to the tip of the root where it connects to the nerves and blood supply of the mouth.

The pulp enables sensations of tooth sensitivity or pain. Cementum The layer of bone-like tissue covering the root. It is not as hard as enamel. Structures around the tooth Periodontal ligament: The periodontal ligament is responsible for attaching the tooth to the jaw bone. It is made up of thousands of fibres which fasten the cementum to the bony socket. These fibres anchor the tooth to the jaw bone and act as shock absorbers for the tooth, which is subjected to heavy forces during chewing. Gingivae (gums): Soft tissue that immediately surrounds the teeth and bone. It protects the bone and the roots of the teeth and provides an easily lubricated surface. Bone: Provides a socket to surround and support the roots of the teeth. Nerves and blood supply: Each tooth and periodontal ligament has a nerve supply and the teeth are sensitive to a wide variety of stimuli. The blood supply is necessary to maintain the vitality of the tooth. Teeth - Anatomy Pictures and Information Home > Skeletal System > Bones of the Head and Neck > Teeth Teeth The teeth are a group of hard organs found in the oral cavity. We use teeth to masticate (or chew) food into tiny pieces.

They also provide shape to the mouth and face and are important components in producing speech. A tooth can be divided into two main parts: the crown and root. Found above the gum line, the crown is the enlarged region of the tooth involved in chewing. Like an actual crown, the crown of a tooth has many ridges on its top surface to aid in the chewing of food. Below the gum line is the region of the tooth called the root, which anchors the tooth into a bony socket known as an alveolus.... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Teeth: Dental Plaque and Periodontal Disease Full Teeth Description [Continued from above] . . . Roots are tapered structures resembling the roots of plants, and each tooth may have between one to three roots. The exterior surface of the root is covered in a bone-like mixture of calcium and collagen fibers known as cementum. Cementum provides grip for the periodontal ligaments that anchor the root to the surrounding alveolus.

Each tooth is an organ consisting of three layers: the pulp, dentin, and enamel. The pulp of the tooth is a vascular region of soft connective tissues in the middle of the tooth. Tiny blood vessels and nerve fibers enter the pulp through small holes in the tip of the roots to support the hard outer structures. Stem cells known as odontoblasts form the dentin of the tooth at the edge of the pulp. Surrounding the pulp is the dentin, a tough, mineralized layer of tissue. Dentin is much harder than the pulp due to the presence of collagen fibers and hydroxylapatite, a calcium phosphate mineral that is one of the strongest materials found in nature. The structure of the dentin layer is very porous, allowing nutrients and materials produced in the pulp to spread through the tooth. The enamel – the white, outer layer of the crown – forms an extremely hard, nonporous cap over the dentin. Enamel is the hardest substance in the body and is made almost exclusively of hydroxylapatite. Teeth are classified into four major groups: incisors, canines, premolars, and molars.

Incisors are chisel-shaped teeth found in the front of the mouth and have a flat apical surface for cutting food into smaller bits. Canine teeth, also known as cuspids, are sharply pointed, cone-shaped teeth that are used for ripping tough material like meat. They flank the incisors on both sides. Premolars (bicuspids) and molars are large, flat-surfaced teeth found in the back of the mouth. Peaks and valleys on the flat apical surface of premolars and molars are used for chewing and grinding food into tiny pieces. Babies are born without teeth, but grow a temporary set of twenty deciduous teeth (eight incisors, four canines, and eight molars) between the ages of six months and three years. Baby teeth fill the child’s tiny jaws and allow the child to chew food while larger, stronger adult teeth develop inside the mandible and maxilla bones. At about six years of age the deciduous teeth are slowly shed one at a time and replaced by permanent adult teeth. Adult teeth develop while hidden within the maxilla and mandible after the deciduous teeth have erupted. When an adult tooth erupts, it triggers the roots of the deciduous tooth above it to atrophy.

This causes the baby tooth to become loose and eventually fall out. The new permanent tooth slowly pushes up through the gums to replace the baby tooth. Eventually, a total of thirty-two permanent adult teeth form and erupt. The adult teeth are arranged in both the upper and lower jaws from the midline of the mouth as follows: central incisor, lateral incisor, canine (cuspid), first premolar (bicuspid), second premolar, first molar, second molar, and third molar. The first twenty-eight adult teeth are fully erupted by the age of eleven to thirteen with the third molars, known as wisdom teeth, erupting in the back of the jaw several years later in early adulthood. Sometimes the wisdom teeth become impacted when they grow and become wedged at an abnormal position in the jaws and fail to erupt. In some cases there is not enough room in the jaw to accommodate a third set of molars. In both cases the wisdom teeth are surgically removed, as they are not needed to properly chew food. Mastication, or chewing, is the main function of the teeth. The teeth are aligned in the jaws so that the peaks of one tooth align with the valleys of its counterpart on the other jaw.

Every bite forces food into the interface of the teeth to be chopped, while lateral motion of the jaw is used to grind food in the premolars and molars. Tooth decay and cavities are important health concerns related to the teeth. The enamel that covers the crown in each tooth can be broken down by acids produced by bacteria that live in the mouth and assist in digestion of small bits of food. This process of enamel erosion by acids is called decay. To prevent decay, good oral hygiene, consisting of daily brushing and flossing, is necessary. Decay can eventually lead to cavities, also known as dental caries, where holes appear in the enamel and expose the dentin. Cavities require medical intervention to prevent their growth, usually resulting in the removal of the affected tissue and the filling of the cavity with a hard material to restore the strength and function of the tooth. Prepared by Tim Taylor, Anatomy and Physiology Instructor

Question: The periodontal ligaments are the supporting tissue for which parts of the human body?
Answer: TEETH